Electrochromic devices, assemblies incorporating electrochromic devices, and/or methods of making the same

ABSTRACT

Certain example embodiments of this invention relate to electrochromic (EC) devices, assemblies incorporating electrochromic devices, and/or methods of making the same. More particularly, certain example embodiments of this invention relate to improved EC materials, EC device stacks, high-volume manufacturing (HVM) compatible process integration schemes, and/or high-throughput low cost deposition sources, equipment, and factories.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Application Ser. No.61/237,580, filed on Aug. 27, 2009, the entire contents of which arehereby incorporated herein by reference.

FIELD OF THE INVENTION

Certain example embodiments of this invention relate to electrochromic(EC) devices, assemblies incorporating electrochromic devices, and/ormethods of making the same. More particularly, certain exampleembodiments of this invention relate to improved EC materials, EC devicestacks, high-volume manufacturing (HVM) compatible process integrationschemes, and/or high-throughput low cost deposition sources, equipment,and factories.

BACKGROUND AND SUMMARY OF EXAMPLE EMBODIMENTS OF THE INVENTION

Windows provide natural light, fresh air, access, and connection to theoutside world. However, they also represent a significant source ofwasted energy. With the growing trend in increasing the use ofarchitectural windows, balancing the conflicting interests of energyefficiency and human comfort is becoming more and more important.Furthermore, the concerns with global warming and carbon foot-prints areadding to the impetus for novel energy efficient glazing systems.

In this regard, windows are unique elements in most buildings in thatthey have the ability to “supply” energy to the building in the form ofwinter solar gain and daylight year around. In current applications,they are responsible for about 5% of the entire U.S. energy consumption,or about 12% of all energy used in buildings. Current window technologyoften leads to excessive heating costs in winter, excessive cooling insummer, and often fails to capture the benefits of daylight, that wouldallow lights to be dimmed or turned off in much of the nation'scommercial stock. These factors result in an energy “cost” of over 5Quads: 2.7 Quads of energy use annually in homes, about 1.5 Quads in thecommercial sector, and another 1 Quad of potential lighting energysavings with daylight strategies. Advances have been made over the lasttwo decades primarily in reducing the U-value of windows through the useof static low-E coatings, and by reducing the solar heat gaincoefficient, SHGC, via the use of spectrally selective low e coatings.However, further enhancements are still possible.

With the ability to dynamically control solar heat gain, loss, and glarewithout blocking the view, electrochromic windows (ECWs) may provide asignificant reduction in energy use. Indeed, ECWs have the potential toimpact all the window energy end uses, e.g., by reducing cooling loadsin climates where windows contribute to substantial cooling loads whileallowing the same window to admit solar gain in winter to reduceheating, and modulating daylight to allow electric lighting to bereduced in commercial buildings while also controlling glare. Forexample, as the exterior light and heat levels change, the performanceof the window can be automatically adjusted to suit conditions via anautomated feedback control.

Electrochromic (EC) windows are known. See, for example, U.S. Pat. Nos.7,547,658; 7,545,551; 7,525,714; 7,511,872; 7,450,294; 7,411,716;7,375,871; and 7,190,506, the disclosure of each of which isincorporated herein by reference.

Some current EC dynamic windows provide transmissions ranging from about3% in the tinted state to about 70% in the clear state. As indicatedabove, the solar heat gain control (SHGC) range is quite large. Indeed,some current EC dynamic windows provide an SHGC range from about 0.09 inthe tinted to about 0.48 in the clear state. Lithium based-inorganic ECtechnology also offers the advantages of durability, low voltage (lessthan about 5V) operation, clarity (70%), transparency when power is off,and low energy consumption. Despite these broad ranges, currentlithium-based inorganic ECWs unfortunately offer limited colorvariation, and maximum opacity could be improved (e.g., relative toother switchable glazing types). Another drawback with currentlithium-based inorganic ECWs relates to their slow switching times.Indeed, current switching times for lithium-based inorganic ECWstypically range from about 5-10 minutes. Proton-based inorganic andorganic polymer device mechanisms switch somewhat faster (e.g., 15seconds to 5 minutes) but unfortunately suffer from degradation of theionic conductor in the former case and degradation of the polymer in thelatter case. The operational voltage for lithium based inorganic as wellas proton-based inorganic and organic polymer type EC devices typicallyoperate with 1-5 V DC and typically consume 2-3 W/m² when switching and0.5-1 W/m² while maintaining the tinted state.

FIG. 1( a) is a schematic diagram of a typical electrochromic window,and FIG. 1( b) is a schematic diagram of a typical electrochromic windowin a tinted or colored state. The active stack 100 shown in FIG. 1( a)includes four components, namely, first and second transparent currentcollectors 102 and 104; a cathode 106 (and often the coloration layer);an electrolyte 108 (which is ionically conducting but electricallyinsulating); and an anode 110, which is the source of the active ions(e.g. Li, Na, H, etc.) that switch the glazing properties upon transferto and from cathode. The anode 110 may be a coloration layer, ifcoloration occurs anodically, e.g., as ions exit the layer. Thesecomponents are sandwiched between first and second glass substrates 112and 114. Fundamentally, the electrochromic device dynamically changesoptical absorptivity, with the movement (intercalation andde-intercalation) of the Li into and out of the cathode 106. This, inturn, modulates the interaction with solar radiation thereby modulatingthe SHGC for energy control, as well as visibility and glare (importantfor human comfort). Because Li is in the cathode 106, the electrochromicwindow in a tinted or colored state and only a portion of incident lightand heat are transmitted through the ECW.

Unfortunately, current ECW films do not meet the required performance inappearance (including color), switching speed, quality consistency, andlong term reliability. Adequate supply and useful window sizes areadditional issues.

One reason the current high ECW cost structure is above the marketthreshold is that the EC device fabrication is incompatible thefabrication flow of the glazing industry. One critical safetyrequirement in the building code is that the outermost glass in aninsulated glass unit (IGU) be tempered. Also, according to practice inthe coated glass industry, large sheets of glass (typically up to 3.2 mwide) are first coated, then sized, and finally tempered. In an idealsituation, the EC finished glass could be tempered and cut to size.However, tempered glass cannot be cut. Accordingly the practice in thecoated glass industry is that large sheets of glass (typically up to 3.2m wide) are first coated and then sold to the window fabrication siteswhere they are sized and tempered. Unfortunately, tempered glass cannotbe cut afterwards, and the EC glass cannot be tempered after ECfabrication because the tempering temperatures would destroy the ECdevice. Consequently, current ECW fabrication techniques rely on alreadycut and tempered glass for EC fabrication. This is problematic forseveral reasons. For example, incoming tempered glass has a widevariation in thickness leading to substantial variation in theproperties of the coating. Additionally, the presence of multiplesubstrate sizes and types leads to challenges in process control,throughput, and yield, which makes reproducible high yielding highvolume manufacturing difficult.

FIG. 2 is a block diagram illustrating a current ECW fabricationprocess. The outermost glass is cut to size and tempered in 202, whichcorresponds to an EC glass fabrication process. The EC device isfabricated, e.g., so that it has the layer structure shown in FIG. 1(a), in 204. After the EC layers have been deposited, the EC device ispatterned in 206, e.g., to reduce defects and improve yield andappearance. Bus bars are added to provide “electrification” (e.g.,wiring) for the EC device in 208. A second substrate is added in spacedapart relation to the EC device, e.g., as shown in FIGS. 1( a) and 1(b).Together, 204, 206, 208, and 210 represent an insulating glass (IG) unitfabrication process. This IG unit may ultimately be incorporated into anECW, e.g., as shown on the left-hand side of FIG. 1( b).

Another impediment to progress has been the limited resources andcapabilities of the manufacturers in developing deposition sources,platforms, and automation that are compatible with high-throughputlarge-scale manufacturing techniques.

The most practical place to have the EC coating is on the inner surfaceof the outermost lite. The placement of bus bars on this surface forelectrification (e.g., wiring) presents challenges not only to currentIG fabricators, but also to glazers. Architects, commercial buildingowners, and end-users require information about the durability of the ECwindow over long durations of time. The reliability of the IG unit sealtherefore is a concern. The EC IG unit differs from conventional windowsin that interconnections to power the device must pass through themoisture barrier seal. There are no standards for interconnects andfeed-throughs that preserve the seal integrity. What is on the market isproprietary. There are also concerns about the durability of the EC filmstack when exposed to the range of solar and environmental stresses thata window experiences over its lifetime.

Finally, the device performance in terms of appearance, color, switchingspeed, consistency, SHGC range, and lifetime needs consideration. Forexample, architects have a strong preference for a neutral coloredwindow that switches from dark gray to perfectly clear. Most EC windowson the market today exhibit a dark blue hue when colored and a yellowishtinge in the clear state. A more neutral color and enhanced transmissionin the clear state would broaden the accessible architectural market.

Thus, it will be appreciated that there is a need in the art forimproved electrochromic dynamic windows, and/or methods of making thesame. For example, it will be appreciated that there is a need in theart for (1) low cost, large scale, high throughput coating techniquesthat are compatible with high-volume manufacturing (HVM); (2) a betterperforming EC formulation; (3) a robust, high throughput, low defect ECformation for large-size lites; and/or (4) coupling such newmanufacturing techniques with existing post-glass fabrication and theancillary technologies for producing complete windows. These and/orother techniques may help solve some of the above-noted and/or otherproblems, while also providing for more complete building controlintegration.

Certain example embodiments relate to top-down and/or bottom-up changesto (a) materials, (b) the electrochromic device stack, (c) high volumecompatible process integration schemes, and (d) high throughput, lowcost deposition techniques and equipment. In so doing, certain exampleembodiments may be used to provide reduced cost EC assemblies, en routeto “Net-Zero Energy Buildings.”

One aspect of certain example embodiments involves the incorporation ofnovel electrochromic materials. For example, certain example embodimentsinvolve an optically doped cathode and/or anode for greater visibletransmission in the clear state, greater solar heat gain control (SHGC)delta between these states, improved appearance, and better reliability.Controlling the stoichiometry of WO_(x) (e.g., so that it issub-stoichiometric) advantageously may result in improvements withrespect to the SHGC delta and better appearance (e.g., in terms ofcoloration). Anodically coloring the counter electrode also may increasethe SHGC delta.

Another aspect of certain example embodiments involves the incorporationof a novel electrochromic device stack. For example, the inclusion of alow-cost, low-Fe mid-lite substrate may help reduce the need forsubstrate-device barrier layers. An improved transparent currentcollector (TCC) with much higher conductivity and transmittance than ITOmay be provided for increased switching speed and reduced cost. Theinclusion of a lithium phosphorus oxynitride (LiPON) electrolytematerial may be selected for reliability purposes in certain exampleembodiments. Additionally, the use of transparent dielectric/conductivelayers may be used to shift the color based on selective interference incertain example embodiments.

Still another aspect of certain example embodiments involves noveltechniques for electrochromic device integration. For example, certainexample embodiments may involve the use of laminated/bonded glass forthe outer lite of EC IG unit. This may advantageously result in thecomplete elimination of the use of tempered glass in EC fabricationstep, reduce the need for glass sizing and tempering before ECprocessing, enable the use of a single standard type and sized glass inEC fabrication for best process reproducibility and economy of scale,and/or enable post-EC fabrication sizing of glass. It also mayadvantageously enable device patterning after all EC layers have beendeposited, thereby reducing the likelihood of defects and improvingyield and appearance.

Yet another aspect of certain example embodiments relates toHVM-compatible deposition source development. For example, a novel LiPONdeposition source capabile of achieving high deposition rates andmodulating growth kinetics may, in turn, enable high throughput andbetter film characteristics in certain example embodiments. Certainexample embodiments also may use a novel linear showerhead based Lievaporator with remote, normal ambient compatible Li sources.

In certain example embodiments, a method of making electrochromicwindows is provided. A first glass substrate is provided. Electrochromicdevice layers are disposed on the first substrate, with such layerscomprising at least counter electrode (CE), ion conductor (IC), andelectrochromic (EC) layers. The electrochromic device layers arepatterned, and the first glass substrate with the electrochromic devicelayers disposed thereon is cut so as to form a plurality of EC devicesubstrates. A plurality of second glass substrates is provided. Theplurality of EC device substrates is bonded or laminated to theplurality of second glass substrates, respectively. A plurality of thirdglass substrates is provided. A plurality of insulating glass (IG) unitsis formed, respectively comprising first and second substrates insubstantially parallel, spaced apart relation to the third glasssubstrates.

In certain example embodiments, a method of making an electrochromic(EC) assembly is provided. First, second, and third glass substrates areprovided, wherein the second substrate is thermally tempered and thefirst substrate is not thermally tempered. A plurality of EC devicelayers are sputtering-deposited, directly or indirectly, on the firstsubstrate, with the plurality of EC device layers comprising a firsttransparent conductive coating (TCC), a counter electrode (CE) layer,ion conductor (IC) layer, an EC layer, and a second TCC. The first andsecond substrates are laminated or bonded to one another. The second andthird substrates are provided in substantially parallel and spaced apartrelation to one another. The CE and EC layers are both color changeablewhen the EC assembly is in operation.

In certain example embodiments, a method of making an electrochromic(EC) assembly is provided. A plurality of EC device layers aresputtering-deposited, directly or indirectly, on a first substrate, withthe plurality of device layers comprising, in order moving away from thefirst substrate, a first transparent conductive coating (TCC), a cathodelayer, an electrolyte layer, an anodically coloring anode layer, and asecond TCC. The first substrate with the plurality of device layerssputter-deposited thereon is connected to a second substrate such thatthe first and second substrates are in substantially parallel and spacedapart relation to one another.

In certain example embodiments, an electrochromic (EC) assembly isprovided. First, second, and third glass substrates arc provided, withthe second and third substrates being substantially parallel to andspaced apart from one another. A plurality of sputter deposited ECdevice layers are supported by the first substrate, with the pluralityof EC device layers comprising a first transparent conductive coating(TCC), a counter electrode (CE) layer, ion conductor (IC) layer, an EClayer, and a second TCC. The first and second substrates are laminatedor bonded to one another. The second substrate is thermally tempered andthe first substrate is not thermally tempered.

In certain example embodiments, an electrochromic (EC) assembly isprovided. At least first and second glass substrates are provided, withthe first and second substrates being substantially parallel to andspaced apart from one another. A plurality of sputter deposited devicelayers are supported by the first substrate, with the plurality of ECdevice layers comprising a first transparent conductive coating (TCC), adoped and anodically coloring counter electrode (CE) layer, an ionconductor (IC) layer, a doped EC layer comprising WOx, and a second TCC.

In certain example embodiments, an electrochromic device including aplurality of thin-film layers supported by a first substrate isprovided. The plurality of layers comprises a doped and anodicallycoloring anode layer; an electrolyte layer comprising Li; and a dopedcathode layer comprising WOx.

The features, aspects, advantages, and example embodiments describedherein may be combined to realize yet further embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages may be better and morecompletely understood by reference to the following detailed descriptionof exemplary illustrative embodiments in conjunction with the drawings,of which:

FIG. 1( a) is a schematic diagram of a typical electrochromic window;

FIG. 1( b) is a schematic diagram of a typical electrochromic window ina tinted or colored state;

FIG. 2 is a block diagram illustrating a current ECW fabricationprocess;

FIG. 3 is a block diagram illustrating an ECW fabrication process inaccordance with an example embodiment;

FIG. 4 is an illustrative electrochromic substrate and stack inaccordance with an example embodiment;

FIG. 5 is an illustrative transparent conductive coating (TCC) usable inconnection with certain example embodiments;

FIG. 6( a) is a first illustrative electrochromic insulating glass (IG)unit in accordance with an example embodiment;

FIG. 6( b) is a second illustrative electrochromic insulating glass (IG)unit in accordance with an example embodiment;

FIG. 7 is a third illustrative electrochromic insulating glass (IG) unitin accordance with an example embodiment;

FIG. 8( a) is an SEM image of a 600 nm Al layer deposited byconventional evaporation; and

FIG. 8( b) is an SEM image of a 600 nm Al layer deposited using aplasma-activated evaporation in accordance with certain exampleembodiments.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

One aspect of certain example embodiments involves the incorporation ofnovel electrochromic materials. For example, certain example embodimentsinvolve an optically doped cathode and/or anode for greater visibletransmission in the clear state, greater solar heat gain control (SHGC)delta between these states, improved appearance, and better reliability.Controlling the stoichiometry of WO_(x) (e.g., so that it issub-stoichiometric) advantageously may result in improvements withrespect to the SHGC delta and better appearance (e.g., in terms ofcoloration). Anodically coloring the counter electrode also may increasethe SHGC delta.

Another aspect of certain example embodiments involves the incorporationof a novel electrochromic device stack. For example, the inclusion of alow-cost, low-Fe mid-lite substrate may help reduce the need forsubstrate-device barrier layers. An improved transparent currentcollector (TCC) with much higher conductivity and transmittance than ITOmay be provided for increased switching speed and reduced cost. Theinclusion of a lithium phosphorus oxynitride (LiPON) electrolytematerial may be selected for reliability purposes in certain exampleembodiments. Additionally, the use of transparent dielectric/conductivelayers may be used to shift the color based on selective interference incertain example embodiments.

Still another aspect of certain example embodiments involves noveltechniques for electrochromic device integration. For example, certainexample embodiments may involve the use of laminated/bonded glass forthe outer lite of EC IG unit. This may advantageously result in thecomplete elimination of the use of tempered glass in EC fabricationstep, reduce the need for glass sizing and tempering before ECprocessing, enable the use of a single standard type and sized glass inEC fabrication for best process reproducibility and economy of scale,and/or enable post-EC fabrication sizing of glass. It also mayadvantageously enable device patterning after all EC layers have beendeposited, thereby reducing the likelihood of defects and improvingyield and appearance.

Yet another aspect of certain example embodiments relates toHVM-compatible deposition source development. For example, a novel LiPONdeposition source capable of achieving high deposition rates andmodulating growth kinetics may, in turn, enable high throughput andbetter film characteristics in certain example embodiments. Certainexample embodiments also may use a novel linear showerhead based Lievaporator with remote, normal ambient compatible Li sources.

Certain example embodiments involve changes to EC materials, the ECdevice stack, HVM compatible process integration schemes, and/orhigh-throughput low cost deposition sources, equipment, and factories.These aspects of certain example embodiments are discussed, in turn,below.

Certain example embodiments relate to advantages in terms of one or moreof cost, device performance, durability, aesthetics, and/or scalability.For example, some current electrochromic products cost more than $50/sq.ft., whereas the techniques of certain example embodiments may provideelectrochromic products at a cost that preferably is less than $25/sq.ft., more preferably less than $20/sq. ft., and still more preferablyless than $15/sq. ft. Although it is difficult to run wiring and controlinfrastructure for current products, certain example embodiments mayprovide for relatively simple modular products, with wireless poweringand/or control options. Although many current products can achieve aswitching speed of 3-5 minutes at best, certain example embodiments mayprovide a switching speed of less than 3 minutes, more preferably lessthan 2 minutes, and sometimes even less than 1 minute, even though theoverall product size may be increased. Advantageously, delta E may beless than about 1.5, more preferably less than about 1.25, and stillmore preferably less than about 1. In terms of color/hue, certainexample embodiments may reduce the yellowish hue in the clear state andthe multiple colors that sometimes are present in the tinted state,instead providing a more neutral color in the clear state with a choicefrom one of multiple colors in the tinted state. Furthermore, certainexample embodiments may reduce switching uniformity problems, e.g., bycausing the latitude to at least appear to change “all at once” (atleast as compared to the variability in shade lines and individualcontrols in current systems). Finally, although current EC devicesgenerally are limited to 1 m wide designs, certain example embodimentsmay scale up to 3.2m wide (or even wider) designs so as to be in-linewith commonly available stock glass sheets.

Example Fabrication Processes

FIG. 3 is a block diagram illustrating an ECW fabrication process inaccordance with an example embodiment. The FIG. 3 process differs fromthe FIG. 2 process in several ways, owing to the fact that the FIG. 3process is designed to provide an EC device on an EC substrate that maybe bonded, laminated, or otherwise connected to a temperable substrate.For example, a material such as PVB, EVA, or the like may be used, asmay “optibond technology,” which is commercially available from Litemax.The laminate that is used may incorporate a UV blocker (e.g., a UVAblocker). Preferably, a UVA blocker may be included, with Tuv<1%, morepreferably <0.75%, and still more preferably <0.5%. The UV blocker may athin film coating comprising one or more of Bi, BiO, Zn, ZnO, TiO,BiSnO, AgO, Ce, CeO, and/or the like. Alternatively, or in addition, aPET coating may be provided, with a UV blocking material providedthereon and/or therein. It will be appreciated PET layer may be providedin certain example embodiments. It will be appreciated that organicand/or inorganic materials may be used in connection with certainexample embodiments. In any event, the laminate may be selected so thatits refractive index matches with the adjacent layers and/or substrates.This advantageously will help keep reflectance low. Reflectance also maybe lowered, e.g., by incorporation of one or more anti-reflective (AR)layers. Because the EC device is provided on a separate substrate thatmay be later bonded, laminated, or otherwise connected to a temperablesubstrate, efficiencies can be realized, e.g., in that larger sheets canbe sputter-coated or the like and later cut to size. Example structuraldetails are provided below.

In terms of the example process shown in FIG. 3, large size glass isprovided in 302. An EC device is fabricated according to the exampletechniques described below in 304. Device patterning and sizing iscarried out in 306, thereby forming a plurality of EC devices on aplurality of corresponding EC substrates. As indicated above, this is anadvantage over the conventional process shown in FIG. 2, whereindividual EC devices are fabricated directly on individually pre-cutindividually already-tempered substrates. In any event, bus bars areconnected and the EC device is “electrified” (e.g., wired) in 308. Thebus bars may be formed by selectively laser etching away layers tocarefully expose the TCC. For example, to selectively etch andelectrically connect the device, both “full” and “half' cuts may bemade, e.g., to expose the bottom and top TCCs. The laser power may becontrolled to selectively remove some or all of the layers in thismanner,

In 310, the outer substrate to which the EC device and substrate is tobe connected is sized and tempered. Then, in 310, the appropriatelysized EC devices are laminated, bonded, or otherwise connected to theappropriately sized outer substrates. The sub-assemblies comprising theEC devices laminated, bonded, or otherwise connected to the outersubstrates are then build into corresponding insulating glass (IG) unitsin 314, e.g., as described in greater detail below.

Example Electrochromic Stack, and Example Materials Used Therein

FIG. 4 is an illustrative electrochromic substrate and stack inaccordance with an example embodiment. FIG. 4 incorporates anelectrochromic stack 400 that is somewhat similar to knownelectrochromic stacks in that it incorporates conductive layers (TCCs),an electrochromic (EC) layer, a counter electrode (CE) layer, and an ionconductor (IC) layer. However, the FIG. 4 electrochromic stack 400differs from current stacks in terms of materials, overall stack design,and performance characteristics. For example, thermal performance, ECspeed, long-term EC reliability, and aesthetics may be improved, e.g.,optimize the performance of known materials and develop new materialsystems that further improve performance of the overall EC device. Thechanges to the materials and stack designs are described in theparagraphs that follow.

A first area of innovation involves the cathode/EC and anode/CEelectrode materials. The thermal performance of an ECW is related to therange of SHGC between clear and tinted states. To increase the SHGCrange, the absorptivity of either or both of the cathode and anodelayers may be reduced in the clear state, and/or an anodically coloringcounter electrode may be created to lower the transmission (T_(v)) inthe colored state. The appropriate material selection may also increasereliability and switching speed.

These and/or other aspects may be accomplished by the substitutionaldoping of active electrode materials in certain example embodiments. Acounter electrode typically includes NiO, with Li+ or H+ ions. Asdescribed above, improving thermal performance, lowering absorbance, andimproving reliability and stability of conductive electrode CE areadvantageous. By using additives such Mg, Al, Si, Zr, Nb and Ta, asignificant reduction of EC and CE film absorbance may be achieved,especially at short wavelengths. On the other hand, films containing Vand Ag have not show the same improvements in optical propertiescompared to those of pure nickel oxide. As such, Mg and/or other elementincorporation, in a combinatorial fashion, may be used to optimize itsbeneficial effect in both NiO and LiNiO systems for widening the bandgap and improving the transmittance substantially. Alternatively, or inaddition, the inclusion of W into the LiNiO also is possible in certainexample embodiments, and it may be used to improve the stability as a CElayer to UV radiation and moisture. This and/or other substitutionaldoping may be used to increase electrical conductivity (in some cases by3 orders of magnitude, e.g., LiCoO₂ vs. LiCo_(0.95)Mg_(0.05)O₂).Surprisingly and unexpectedly, doping the CE (and/or the IC) with Mgalso makes it a “faster” conductor.

certain example embodiments also may involve anodically coloring thecounter electrode, e.g., for improved thermal performance. As is known,the CE is used to store the charge, which is in turn used to color theelectrochromic layer. To do this effectively, the CE layer may allowcharges to intercalate easily; be stable and durable to repeatedcycling; and be very transparent in the clear state; and if possible,display electrochromism when fully discharged of intercalated ions(e.g., anodically). Thus, in certain example embodiments, the CE may bemade electrochromic. However, in such example embodiments, the CE may bethe “reverse” of the EC layer, e.g., such that it becomes transparentwith ions, and provides for a color change on ion loss. To realize theseand/or other features, certain example embodiments may incorporate a CEbased on NiO systems that have been shown to be stable upon repeatedcharge insertion/extraction cycling. These systems sometimes display asmall amount of residual absorption when the device is fullyintercalated, e.g., in Li_(x)NiO_((i+y)) state in the reaction shownbelow. The challenge is to remove this absorption without sacrificingthe wide dynamic range and good switching kinetics of the device. Thesubstitutional doping, analogous to the discussion in previous section,using Li may induce better T_(v) and remedy the small absorbance that iscounter to increasing the SHGC delta.

The tendency for water to cause deterioration in NiO_((1+y)) hydratedsystems has now been confirmed. Consequently, non-aqueous basedelectrolytes and the cubic form of lithium nickel oxide may be apromising electrochromic system in certain example embodiments. Forexample, nanocrystalline Li_(x)Ni_(1-x)O may have a wide optical dynamicrange and more neutral color than tungsten oxide, as well as betterstability. Furthermore, may be anodically coloring, thereby providingthe advantage of being complementary to cathodic tungsten oxide. Acombination of these materials may be favorable with regard toelectrochemical potentials, and as well as attaining a neutral deepercolor in the dark state. The photopic coloration efficiency of thisanodically coloring material typically is high. The switchingperformance of a device utilizing a solid state electrolyte as well as alithium nickel oxide film as counter electrode and a tungsten oxideelectrochromic film has certain advantages over currently availablesystems. It is noted that the main reaction at the basis of thiselectrochromic activity is:

NiO_((1+y))+x(Li⁺+e)→Li_(x)NiO_((1+y))

-   -   Dark Colorless

In certain example embodiments, the absorptivity and/or color modulationof the EC tungsten oxide (WOx) may be altered for thermal performanceand appearance. Stoichiometric WO₃ films are transparent for energiesbelow the fundamental band gap at <3 eV. Li ion intercalation leads toelectrochromism manifested by a broad absorption band centered at ˜1.2eV, which produces a distinctly blue color. This phenomenon may bedescribed in terms of intervalence charge transfer with electronstransferred from a W⁵⁺ site to an adjacent W⁶⁺ site. The effects ofpolarons may be incorporated into a new model using tight bindingapproximation. According to this self-consistent model, the value of xin slightly sub-stoichiometric WO_(x) can be optimized in certainexample embodiments so that the EC material is yet more transparent and,upon increased lithiation, increases absorptivity. Thesub-stoichiometric value of x preferably is 2.4<x<3; more preferably2.6<x<3. A value of about 2.88 has been found to be particularlyadvantageous. Such values help reduce “yellowness” and improve the depthof color of the EC, which helps improve clear and colored states.

The strong electron-phonon coupling tends to favor the formation of(W-W)¹⁰⁺ complexes, which do not lead to optical absorption. However,singly charged oxygen vacancies yield absorption because ofinter-valence charge transfer. The analogy with data for the ionintercalated film is expected, as W⁵⁺ sites are present in both cases.It thus appears that amorphous tungsten oxide films display a cross-overfrom defects with paired electrons, according to the Anderson mechanism,and singly charged oxygen vacancies as the density of vacancies isincreased.

Furthermore, irreversibility in the charge insertion is commonly foundduring the first color/bleach cycles, and the films remain transparentup to a threshold of inserted charge (called color blind charge)whereupon coloration sets in and subsequent cycles are reversible sothat electrochromism prevails. The lithium is irreversibly incorporatedand is not recovered from the EC film during switching. The blind chargedoes not seem to interfere with the electrochemical kinetics of theinsertion process. However, the variable amount of irreversible Liincorporation makes it hard to precisely determine the amount of labileLi needed for optimal dynamic range of the EC device during switching.In addition, the Li loss is not uniform over large areas of filmdeposited. It therefore will be appreciated that the amount of blindcharge resident in the as-deposited EC films may be controlled. Onesolution involves reducing (or minimizing) the amount of blind-chargepresent in the film by understanding the root cause of the Li “loss.”One solution is related to the type of target used in the deposition ofthe EC material, the addition of an ion beam, and the monitoring of theprocess to judiciously control the stoichiometry of the films.

This solution reduces the need for heating of the substrate. Inparticular, in certain example embodiments, EC films with acceptableelectrochromic properties may be deposited from ceramic targets usingion assisted twin magnetron configurations.

Indeed, certain example embodiments may employ substitutional doping andgrain structure control to modulate the yellowish hue in the clearstate. One concern for ECW is the yellowish baseline color in the clearstate. The root causes are thought to be (1) the structural instabilityof metal oxide units (WO_(x)) with Li insertion/de-insertion cycles,leading to Jan-Teller distortion and corresponding shift in energystructure and color, (2) the base color of NiO_(x) the most frequentlyused base anode material, and (3) interference related to grainboundaries. Doping with appropriate metals (V, Mo, etc., into NiO_(x))and halides (e.g., Cl) may be used in certain example embodiments toaddress a least the first two root causes to change the band gap (andthus the varied light-material interaction) and/or to enhance the WO_(x)structural stability over Li cycling. The grain structure may bemodulated by deposition process optimization in certain exampleembodiments, either with in situ or post-deposition ex situ treatments(e.g., applying substrate bias and microwave enhancements or annealing).This also may be used to enhance the structural stability of WO_(x) overLi cycling.

The IC helps to maintain internal electrical isolation between the ECand CE electrodes while providing ionic conductance for electrochromicbehavior. The stability and reliability of electrochromism depends onthe properties of the electrolyte. Lithium phosphorous oxynitride(LiPON) may be used as the electrolyte layer material in certainexample. The choice is based on its superior reliability and stability,as demonstrated in the thin film battery applications. LiPON is anelectrically insulating material (>1E14 Ω-cm), so RF sputtering istraditionally used and it exhibits a low deposition rate (<1 μm/hr).This low deposition rate may be improved as discussed below, and/orother materials and methods that are more amenable to high throughputproduction may be used in connection with certain example embodiments.

It will be appreciated that it would be advantageous to reduce theelectronic leakage current taking place through the IC. The leakagecurrent can be split into contributions that are associated with thethin film stack itself (diffusion limited), and that are associated withlocalized point defects, (both bulk and interfacial). One can model theEC/IC/sCE interfaces as heterojunctions. It is advantageous to stabilizethe junction to subsequent thermal processing. The forward and reversebarrier heights for the EC/CE junction may be optimized by altering thecomposition, structure, and interface chemistry of the IC. The evidencesuggests that leakage current may be reduced to negligible levelsthrough selection of appropriate process and materials for the IC layer.Accordingly, certain example embodiments provide an IC layer where theintegrity of the electron barrier structure is maintained with adequateionic conductivity. In practice, higher ionic conductivity typicallyrequires a more porous, amorphous structure, and possible incorporationof lithium, both of which may degrade the electron barrierfunctionality. The materials stack described herein, and the respectivedeposition processes described below, help alleviate these concerns.Furthermore, in certain example embodiments, the optical indices of thematerials may be matched to the surrounding layers.

As shown in FIG. 4, the EC device stack 400 may include a firsttransparent conductive coating (TCC) 404, a counter electrode layer 406,an ion conductor layer 408, an electroehromic layer 410, and a secondTCC 412. Each of the first and second TCCs 404 and 412 may be about 200nm thick in certain example embodiments. An example layer system for oneor both of the TCCs is provided below, e.g., in connection with FIG. 5.The anodic CE layer 406 may be about 100-400 nm thick, and it mayinclude NiO and contain Li+ or H+ ions. A LiPON-based IC/electrolytelayer 408 may be about 1-3 microns. Similar to the CE layer 406, the EClayer 410 may be 100-400 nm thick. Either or both of the CE layer 406and the EC layer 410 may be doped, e.g., to provide for better and/ordeeper coloration. Optionally, a barrier layer (not shown in the FIG. 4example) may be provided over the outermost TCC 412, and such a barrierlayer may enable color shift. In certain example embodiments, theoutermost TCC 412 itself may enable color shift. The EC device stack 400is provided on an EC substrate 402 which may, in certain exampleembodiments, be provided as a standard size/thickness large substrate.Indeed, in certain example embodiments, the EC substrate 402 may be alow iron, non-tempered substrate that is cut after the EC device isfabricated on it. Example low-iron glass substrates are disclosed in,for example, U.S. application Ser. No. 12/385,318, as well as in U.S.Publication Nos. 2006/0169316; 2006/0249199; 2007/0215205; 2009/0223252;2010/0122728; and 2009/0217978, the entire contents of each of which arehereby incorporated herein by reference.

The EC device stack design shown in FIG. 4 and described herein differsfrom current designs in a number of respects including, for example, theuse of the novel transparent conductor described below, multipledielectric layers for interferometric color shift, low Fe and low costsubstrates on which the EC layers are formed, LiPON as the electrolyte,and stack thickness optimization. These factors each affecttransmittance, color, transition speed and cost, as described elsewhere.

The switching speed of an EC device is limited by the sheet resistanceof the TCO layers, although voltage drop in the EC layer alsocontributes to delays. This is because the voltage that can be appliedto the device is fixed, and the amount of charge that must betransferred in order to fully color the device scales with the area.Given a series of devices of fixed length, but with progressively largerwidths, as the separation between the bus bars gets larger, theimpedance of the EC stack itself (the part of the device where thecurrent travels perpendicular to the surface of the glass) gets smaller.In contrast, the impedance of the TCO layers where the current isflowing parallel to the surface of the glass gets larger. Overall, thischange in area leads to a larger potential drop in the TCO layers. Thisresults in a lower potential applied directly to the stack, leading toslower switching. Thus, it will be appreciated that to increase theswitching speed of reasonably sized devices, e.g., suitable forarchitectural applications, the conductivity of the TCO layers may beincreased.

It is possible to increase the conductivity of the upper TCO by simplymaking it thicker. However, this approach has certain disadvantages. Forexample, this approach introduces additional absorption and reflection,thereby reducing the bleached state transmission and decreasing thedynamic range. It also will cause the device to change colorasymmetrically, where the color will appear from one of the bus bars andtravel across to the other side of the device, resulting in a “curtain”or accordion effect. Still further, this approach adds materials andprocessing costs, as ITO (which is expensive) typically is used for theTCO.

To overcome these challenges, certain example embodiments usesilver-inclusive coating stacks. Such stacks may have sheet resistancesat least one order of magnitude lower than those of currently availableTCOs. Additional advantages of this coating include its “low-E”functionality, which helps improve SHGC and UV protection of the activelayers.

FIG. 5 is an illustrative transparent conductive coating (TCC) usable inconnection with certain example embodiments. The example TCC of FIG. 5includes a silver-based layer 506, sandwiched by first and second ITOlayers 502 and 510. First and second interlayers 504 and 508 may beprovided between the silver-based layer 506 and the first and second ITOlayers 502 and 510. Such interlayers may comprise NiCr (e.g., NiCrOx)and/or Cu. The silver-based layer 506 preferably is 100-200 angstromsthick, more preferably 120-180 angstroms thick, and sometimes 140angstroms thick. Each ITO layer preferably is 1000-2000 angstroms thick,more preferably 1200-1600 angstroms thick, and sometimes about 1400angstroms thick. The interlayers preferably are 1-20 angstroms thick,more preferably 5-15 angstroms thick, and sometimes 10 angstroms thick.When so designed, it is possible to provide a TCC that has a sheetresistance preferably less than 20 ohms/square, more preferably lessthan 10 ohms/square, and sometimes as low as 5 ohms/square or evenlower. The visible transmission of such layers may be optimized toprovide visible transmission of preferably 65%, more preferably 75%,still more preferably 80%, and sometimes as high as 85% or higher.Optionally, low-E coatings may be provided between a glass substrate andthe lower-most ITO layer in certain example embodiments. Such low-Ecoatings may include layers with alternating high and low indexes ofrefraction, e.g., in a high-low-high-low-high arrangement. Although FIG.5 shows a simple TCC layer stack, other layer stacks also are possible.In certain example embodiments, a suitable TCC layer stack may include2, 3, 4, or more of the layer stack shown in FIG. 5.

In certain example embodiments, the TCCs may be graphene- and/orCNT-based. See, for example, U.S. application Ser. Nos. 12/461,349 and12/659,352, the entire contents of which are hereby incorporated herein.

As indicated above, one issue with current electrochromic devices is theyellowish hue in the clear state and the desired neutral hue in thetinted state. To overcome the challenges, certain example embodimentsuse “color enhancement” multiple layers, which induce color shifting viaFabry-Perot interference. In certain example embodiments, a colorshifting layer stack may be deposited adjacent to the EC coating stack,and it may comprise sputterable insulating and metallic layers. Theoptical properties as well as thickness of the individual layers may beengineered to provide functionality including, for example, enhancedsolar performance, visible color coordinate shifts into a more desirableneutral tone both in the un-tinted and tinted states, and UV screeningto the underlying EC stack, thus prolonging its life. In addition, theselayers may increase the reliability of the EC window, e.g., byfunctioning as a barrier for ambient oxidants when and if the seal inthe IG unit breaks down. It is also feasible to use the TCC, discussedabove to accomplish this functionality.

To reduce the likelihood of diffusion of iron from the glass substrateinto the EC device stack and thus reduce the likelihood of degradation,it is possible in certain example embodiments to use a thin barrierlayer such as a silicon nitride inclusive (e.g., Si₃N₄ or other suitablestoichiometry) layer. However, certain example embodiments may insteaduse a low Fe, lower cost glass product. The use of a suitable low Fe,lower cost glass substrate may reduce and sometimes even eliminate theneed for a barrier layer, thereby leading to a reduction in processcomplexity, improvement in transparency, and lowering EC manufacturingcosts.

The use of LiPON as the IC layer advantageously increases devicereliability. For example, reliability is increased at least in terms oflife cycle by using the most robust and electrochemically stableelectrolyte, (LiPON), which is stable up to 5.5V and against Li metaland whose life cycle in thin film battery application has beendemonstrated to be over 100,000 cycles with minimal losses in capacity.Minimal capacity loss for the battery may translate to a reduced shiftin optical properties in electrochromics.

Stack thickness may be optimized in certain example embodiments toimprove the switching speed of the EC device. For example, one way toimprove the EC device speed is to reduce the thickness of the CE and IClayers. The rate of switching has been found to increase with increasesin lithium levels. However, it also has been found that if the lithiumlevel is increased too far, the devices become electronically “leaky,”thereby failing to become fully colored and also failing to reduce therate of switching. The stack materials and thickness ranges specifiedabove have been found to be advantageous in terms of improve switchingspeed, although it is also possible to adjust the thicknesses andmaterials in other ways in different embodiments.

Example Process integration Techniques

One drawback associated with traditional EC process flows is the needfor substrate sizing and tempering before EC device formation, which isrelated to the fact that post-fabrication tempering will damage the ECdevice and sizing cannot be performed after tempering. This conventionalprocess flow was illustrated in FIG. 2. In this process, any variationin finished product requirement such as, for example, substrate size,thickness or type, etc., tends to lead to a complex device/layermanufacturing environment. For example, the EC coating process will befine-tuned to each product separately for optimum results depending on,for example, the substrate size and thickness. For applications such asECW, with distinct contrast, especially at tinted state, suchnon-uniformity would be detrimental to the product.

However, as indicated above (e.g., in connection with FIG. 3), certainexample embodiments instead involve lamination, a non-tempered singletype of glass for EC fabrication, post-EC fabrication glass sizing, anddevice patterning after blanket deposition of EC layers. From the FIG. 3schematic and description provided above, it will be appreciated thatthere is an absence of tempering, along with the inclusion of laminationsteps.

In this laminated/bonded EC glass concept, the outer window glass (outerlite) includes a two-sheet glass unit. A first sheet is provided for useas the EC sheet, and the other sheet is provided to meet thetempering/safety and other product requirements. This arrangement isshown in FIGS. 6( a) and 6(b), which show cross-sectional views for IGunits in accordance with certain example embodiments. It will beappreciated from FIGS. 6( a) and 6(b) that there are at least twooptions for bonding the EC glass. In the FIG. 6( a) example embodiment,the EC stack faces the open inner space, whereas the EC stack isdirectly bonded to the outer lite in the FIG. 6( b) example embodiment.The FIG. 6( b) example embodiment is particularly advantageous in thatit is perhaps better protected from the breach of IG unit seal. Oneadvantageous consequence of this lamination/bonded concept is that thetempering requirement for the glass used for EC device fabrication cansometimes be completely eliminated. This, in turn, opens the door tousing single type substrates and post-fabrication glass sizing withnon-tempered glass, consistent and compatible with the currentfabrication flows of coated glass and windows. Consequently, this helpslead to a robust and stable production environment for optimal processcontrol, throughput and yield, and to lower cost.

As indicated above, the IG units 600 a and 600 b shown in FIGS. 6( a)and 6(b) are similar to one another. Both include outer glass substrates602 that may be tempered, along with inner glass substrates 604. Thesesubstrates 602 and 604 are substantially parallel to one another andspaced apart, e.g., using spacers 606, thus forming an isolation gap608. A laminate 610 (e.g., a PVB lamination foil, an EVA laminate, anoptibond laminate, etc.) helps connect the outer glass substrate 602 tothe EC glass 402. In FIG. 6( a), the laminate 610 connects the outerglass substrate 602 to the EC glass substrate 402 so that the EC layerstack 400 faces the isolation gap 608. By contrast, in FIG. 6( b), thelaminate 610 connects outer glass substrate 602 to the EC glasssubstrate 402 so that the EC layer stack 400 is provided between thesetwo substrates 602 and 402. Some or all of the substrates may beUltraWhite glass substrates, which are commercially available from theassignee of the instant invention.

The integration modification to pattern the device after all EC layersare deposited is another advantage of certain example embodiments, e.g.,as compared to the conventional process shown in FIG. 2, where multipledevice patterning was needed, e.g., as indicated by the bi-directionalarrow. By patterning after all layers are completed, however, thelikelihood of defects is reduced, leading to better a yield and betterquality ECW. This is related, in part, to the simplified process and thereduced likelihood of cross-contamination issues both the patterningprocess and additional exposure to (potentially unclean) ambient air.

The EC integration flow that includes lamination, bonding, or otherconnection of two glass sheets to form a single outer lite of an IGunit, as illustrated in FIGS. 6( a) and 6(b) for example, may lead toadditional benefits. For example, such designs have the potential forbroadening the product applications, e.g., by flexibly combining thestandard EC glass with any another glass product whose properties can beselected to meet the desired window requirements, including safety,color, sound barrier, and others. This process flow is consistent withthe current value chain of the glass industry and would help broader theapplicable application areas to further amortize the development andcost.

The lamination, bonding, and/or other connection of glass units incertain example embodiments may be similar to those techniques used inboth glass (safety products, etc.) and thin-film solar photovoltaicindustries. Challenges related to thermal cycling and actual temperatureto which the “absorptive” EC device can be subjected may be mitigated,e.g., by selecting the materials so that they match with one another(e.g., in terms of coefficient of thermal expansion, etc.) to helpensure compatibility in potentially harsh environments.

FIG. 7 is a third illustrative electrochromic insulating glass (IG) unitin accordance with an example embodiment. The FIG. 7 example embodimentis similar to the FIG. 6( b) in that sputter-deposited EC layers 400 aredisposed between the outer glass substrate 602 and the mid-lite 402.However, the FIG. 7 example embodiment differs from the FIG. 6( b)example embodiment in that it includes a number of optional low-Ecoatings. In particular, the FIG. 7 example embodiment includes a firstlow-E coating 702 located on an inner surface of the outer glasssubstrate 602, second and third low-E coatings 704 and 706 located onopposing surfaces of the mid-lite 402, and a fourth low-E coating 708 onthe surface of the inner substrate 604 facing the air gap 608. One ormore of the optional low-E coatings may be the SunGuard SuperNeutral 70(SN70) low-E coating commercially available from the assignee, althoughother low-E coatings also may be used. For example, see U.S. Pat. Nos.7,537,677; 7,455,910; 7,419,725; 7,344,782; 7,314,668; 7,311,975;7,300,701; 7,229,533; 7,217,461; 7,217,460; and 7,198,851, thedisclosures of each of which are hereby incorporated herein byreference.

Example High Throughput Sources and Equipment

Certain example embodiments make EC technology more cost-effective byproviding high deposition rate deposition sources to allow highthroughput, low capital intensive EC factories. With respect to sourcedevelopment options, the table below identifies possible depositionmethods for the EC layers usable in connection with certain exampleembodiments. There are two basic approaches for the lithiated layers,namely, single step deposition from a composite target or sequentialdeposition of oxide and lithium. Using highly reactive Li in amanufacturing environment may be problematic. However, using a lithiatedtarget may lead to inconsistency in stoichiometry over the targetlifetime, when a sputtering method is used. In any event, for sputteringtechniques, certain example embodiments may implement a two-step method.E-beam evaporation methods for lithiated metal oxides also may be usedto address potential limitations involved in using the sputteringtechniques.

Step 1 Step 2 Target Sputtering Type Target Sputtering TypeLi_(x)M_(y)O_(z) Li_(x)M_(y)O_(z) pDC or RF in Ar N/A N/A ambientLi_(x)M_(y)O_(z) M_(y)O_(z) pDC or RF in Ar/O₂ Li Evap or Sputt in ArLi_(x)M_(y)O_(z) M DC or pDC in Li Evap or Sputt in Ar/O₂ Ar LiPONLi₃PO₄ RF (in nitrogen N/A N/A ambient) TaO_(x) Ta₂O₅ pDC or RF in ArN/A N/A then O₂ TaO_(x) Ta DC or pDC in O₂ N/A N/A

As indicated above, the LiPON electrolyte may be used in certain exampleembodiments, because of its superior reliability and stability asdemonstrated in the thin film battery applications. LiPON is anelectrically insulating material (greater than 1E14 Ω-cm), soconventional RF sputtering typically exhibits a low deposition rate(less than 1 μm/hr). Conventional deposition of Li by evaporation isalso slow. Accordingly, certain example embodiments may be sped-up so asto be compatible with a high throughput and large area coating system.

To overcome at least some of these conventional problems, certainexample embodiments may implement a multi-frequency based plasmadeposition source, in which higher frequency plasma is superimposed withthe common RF power. This may enhance the control of plasma density andsheath voltage. It also may increase the deposition rate, as well asimpart energy onto the growing film, e.g., to modulate growth kinetics.This may also affect conformality, morphology, crystallinity, and lowpinhole density to yield films with better coating characteristics.This, in turn, will allow the use of thinner electrolytes, leading tohigher manufacturing throughput, and lower impedance EC device withfaster device switching speeds. FIG. 8( a) is an SEM image of a 600 nmAl layer deposited by conventional evaporation. The image in FIG. 8( a)reveals a columnar structure having a rough surface. FIG. 8( b) is anSEM image of a 600 nm Al layer deposited using a plasma-activatedevaporation in accordance with certain example embodiments. That is,FIG. 8( b) shows a multi-plasma sputtering concept for RF-HF combinationsource. The SEM photograph in FIG. 8( b) shows an example of the effectsof imparting energy onto a growing film, which include a denserstructure having a smooth surface.

Current Li evaporation technologies generally are not HVM compatible,inasmuch as they typically require the use of multiple point sources andsubstantial downtime for recharging highly reactive Li or elaborateinert ambient condition to support self feeding from an ex situ source.However, certain example embodiments may incorporate a linear showerheadbased source with a remote Li reservoir that can be replenished withoutdisturbing the process or the vacuum system. Modeling results for theproposed evaporators are shown in the table below. From these results, asingle linear source appears to be sufficient for an HVM system (greaterthan 1 μm/min rate).

Evap. rate Evaporation Static dep. rate T (C.) (kg/(m² * s) rate (kg/s)(nm/hr) 300 5.12E−08 1.01E−10 0 400 6.10E−06 1.20E−08 55 500 2.05E−044.03E−07 1855 600 3.02E−03 5.93E−06 27330

Issues with Li sputtering include “clustering” and low deposition rate,which negatively affect the uniformity. Clustering occurs when thesputtering species is much heavier (e.g., Ar) and the sheath voltage istoo high leading to high momentum. Use of lower atomic weight He and Newill both reduce the deposition rate and incur high cost. Consequently,a multiple-frequency plasma source, analogous to the one proposed forUPON deposition, may be used in certain example embodiments. However, RFmay be superimposed upon DC sputtering to increase the plasma densityand to reduce the sheath voltage. This will allow the use of lower costAr while also reducing clustering.

In terms of HVM development, time savings may be realized in certainexample embodiments, as active layers may be processed in a singleintegrated deposition system where the substrates see only the cleandeposition chambers, thereby reducing yield- and aesthetics-affectingdefects/debris caused by, for example, patterning, substrate sizing,exposure to air, etc. The limited air exposure also reduces clean-roomrequirement and once again leads to overall cost reduction.

In certain example embodiments, the EC layer stack process may be spedup at least 2 times compared to current practices, more preferably atleast 3 times, and still more preferably at least 5 times. Multipletargets (e.g., 2, 3, 4, or even 5 or more targets) may be used in thedeposition process to increase line speed.

Example Electrochromic IG Unit

An example EC IG unit includes a tempered outer substrate, a mid-lite,and an inner substrate. The outer substrate is a 6 mm thick UltraWhitesubstrate, and the mid-lite is a 1 mm thick UltraWhite substrate. Theouter substrate and the mid-lite are bonded together using an optibondlaminate. Electrochromic layers are disposed on the surface of themid-lite that face the outer substrate. The TCCs used in connection withthe electrochromic layers correspond to the FIG. 5 example layer stack.A SunGuard SuperNeutral 70 low-E coating commercially available from theassignee is formed on both sides of the electrochromic layers. The innersusbtrate is a 6 mm thick sheet of Clear glass, commercially availablefrom the assignee. An air gap of 12 mm is present between the mid-lightand the inner substrate. This arrangement may have the following exampleproperties:

Solar Energy Visible Light (Direct) Winter Summer % Reflectance % RU-value U-value Shading Condition % T Indoor Outdoor % T Out Night DayCoef. SHGC RHG LSG Untinted 48 15 18 15 43 .291 .28 .22 .35 49 2.03LiPON Tinted 2 11 9 1 40 .291 .28 .07 .062 17 .36 LiPONAs is known, LSG stands for light-to-solar gain. In the table above, “%R Out” refers to the percent of direct solar energy reflected out.

In certain example embodiments, transmission in the tinted statepreferably is less than 5%, more preferably less than 4%, still morepreferably less than 3%, and sometimes even about 2%. In certain exampleembodiments, transmission in the untinted state preferably is at leastabout 40%, more preferably at least about 45%, and sometimes 48% or evenhigher. SHGC preferably ranges from 0.03 to 0.5.

As used herein, the terms “on,” “supported by,” and the like should notbe interpreted to mean that two elements are directly adjacent to oneanother unless explicitly stated. In other words, a first layer may besaid to be “on” or “supported by” a second layer, even if there are oneor more layers therebetween.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is to be understood that the invention is not to be limited to thedisclosed embodiment, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

1-13. (canceled)
 14. An electrochromic (EC) assembly, comprising: atleast first and second glass substrates, the first and second substratesbeing substantially parallel to and spaced apart from one another; and aplurality of sputter deposited device layers supported by the firstsubstrate, the plurality of EC device layers comprising a firsttransparent conductive coating (TCC), a doped and anodically coloringcounter electrode (CE) layer, an ion conductor (IC) layer, a doped EClayer comprising WOx, and a second TCC.
 15. The assembly of claim 14,wherein the IC layer includes Li.
 16. The assembly of claim 15, whereinthe IC layer includes UPON.
 17. The assembly of claim 14, wherein the CEand. EC layers are doped with Mg.
 18. The assembly of claim 14, whereinthe WOx is substoichiometric.
 19. The assembly of claim 14, wherein theCE and EC layers are both color changeable when the EC assembly is inoperation.
 20. The assembly of claim 14, wherein at least one of thefirst and second substrates is a low-iron glass substrate.
 21. Anelectrochromic device including a plurality of thin-film layerssupported by a first substrate, the plurality of layers comprising: adoped and anodically coloring anode layer; an electrolyte layercomprising Li; and a doped cathode layer comprising WOx.
 22. Theelectrochromic device, wherein the anode and cathode layers are bothelectrochromic color changing layers in operation.